If you are this dad's friend, what can you do to be supportive? How can you help him through the process positively? How can you avoid taking sides or becoming co-dependent and at the same time be there for your friend?
Be a good listener. More than anything, your friend will likely need to do a lot of talking. Even though men aren't "wired" to share their feelings, going through a divorce is an intensely emotional time. So just plan on spending time in a listening mode.
Avoid giving advice or opinions. Men are "wired" to try to solve things, but you will not be able to solve the breakup of your friend's marriage. So consciously avoid giving direct advice. Remember, you are neither his attorney nor his therapist. If you are ever tempted to say something that starts with, "Well, if I were you…" think again.
Help him see it realistically. Often men in this position will have a tendency to either over-react to what is happening or to under-react. Listen to his concerns and offer perspective. Typically, a soon to be ex-wife is not really trying to poison all of his friends or trying to ruin his reputation at work, church or in other circles. But the likelihood of a reconciliation is also not very high. It is important to stay real.
Be aware of critical moments. Understand that your friend may have times when he is more troubled than at other times. There are milestones in the legal process that may cause regret or pain. Birthdays of the kids or other anniversaries and holidays are particularly tough. Be aware of these dates and make a call or a visit on those days.
Don't be their therapist. If the issues in your conversation get a little heavy, remember that you are not a trained therapist or psychoanalyst. Don't try to prescribe answers to emotional problems. Instead, point to resources including perhaps your friend's employee assistance program if one is available or community mental health resources.